<p>The Canadian Security Intelligence Service (CSIS) is an unstudied public safety service responsible for protecting national security and thus the safety of all people in Canada. In the current study, we interviewed CSIS employees (<i>N</i> = 38) to understand their mental health, the implications of their work, and the degree of stigma around mental health in their organization. Findings suggest 61% of interviewees reported being diagnosed with or having symptoms of a mental health disorder, in their adulthood or after beginning their employment. Those without a diagnosis still qualitatively reported symptoms consistent with compromised mental health. Participants from both subgroups spoke of being hypervigilant and their work disturbing their sleep – beyond these effects, these public safety professionals experienced unique forms of mental health stigma, informed through their mandated need to live and work in secrecy. Findings are discussed with considerations aimed at improving employee mental health for CSIS and other public safety sectors, as well as theorized in relationship with the changing understandings of stigma tied to mental health in the public safety realm.</p>